Selector



Aug. 24, 1943. F. A. HUBBARD SELECTOR Filed Dec. 9, 1941 2 Sheets-Sheet l FIG. 4

CODE 2 CODE ANGLE A a LODE ANGLE 4 a ANGLE A a INVENTOR FRANC/S ,4. HUBBARD A T TORNEV 1943- F. A. HUBBARD 2,327,792

SELECTOR Filed Dec. 9, 1941 2 Sheets-Sheet 2 FIG. 8

CIRCUIT ANGLE +B47'TER) BATTERY 0 I6 I G 4 INVENTOR FRANCIS A. HUBBARD Patented Aug. 24, 1943 UNITED STATES PATENT "OFFICE 2,327,792 SELECTOR mm: A. Hubbard, Maplewood, N. 1., assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y., a corporation of New York breaking devices and particularly to selective response switching means.

The object of the invention is to provide a simple and economical relay device which will respond to a plurality of diiierent energizing conditions and selectively operate a corresponding plurality of different circuit paths. By way of example, one object is to providea relay device which will respond to any one of ten different digital circuit conditions set up at a telephone substation for properly recording at a central oiiice the digital designation being thereby transmitted.

The device consists essentially of a two phase motor stator provided with coils in quadrature responsive to signals of varying strength and direction to set up a field in any given direction in combination with responsive rotational means for selectively closing a given circuit. This rotational means may take the form of an electron any work, beyond accelerating its own mass and overcoming the friction of its bearings. It is not necessary to provide any restoring force, since there is no occasion for the unit to start from any specified position. The rotating system therefore is made very light and is capable of reaching the desired position very rapidly. Since it can rotate in either direction, it will never be required to turn through more than 180 degrees.

beam or its mechanical analogue in. which case J signals transmitted over two wires. The control mechanism consists of a stator having two separate windings with their magnetic axes at right angles, like the stator of a two-phase induction motor, and a polarized rotor, preferably using a permanent magnet to provide the polarization. The rotor will take up a position determined by the polarities and relative magnitudes of the currents through the two windings. Attached to the rotor is a shaft with projections arranged helically along it. Adjacent to the shaft is a series of sets of contact springs, placed in a straight line and spaced apart by a distance equal to the axial spacing of the projections along the shaft. The shaft itself, or a sleeve rotating with it and carrying the projections can be moved axially by an auxiliary magnet. The contact springs are so positioned with respect to the shaft that for any angular position of the shaft, one and only one of the projections is immediately adjacent to the corresponding set of contact springs; and when the shaft is moved axially, that one projection will engage with and operate its particular set of springs. Thus, any set of springs can be selected by applying a particular combina tion of currents to the two windings of the stator, and those springs will then be operated by the auxiliary magnet.

The rotating system is not required to perform In accordance with another embodiment of the invention the auxiliary magnet operates on the springs rather than on the shaft or an attached sleeve.

In accordance with still another embodiment of the invention the contact springs are arranged in a circle around the stator structure and the shaft withits helically arranged projections is replaced by a disc containing a single spring operating finger, or selecting member corresponding to the polarization of the rotor. In this case the auxiliary magnet applies force to the contact springs and only that set which is in cooperative relationship with the operating finger is able to operate.

In another embodiment of the invention only a-portion of the possible angular range of the .rotor is employed since the stator is energized by direct current in a circuit arrangement designed to provide operation where there is a variable ground potential between the relay and the dis- Since currents of opposite polarities cannot be used, only the first and third quadrants can be utilized.

In another embodiment of the invention, the mechanical rotor is replaced by an electronic tube similar to that disclosed in Patent 2,217,774

, granted October 15, 1940 to A. M. Skellett. By

made in one case to provide twelve selective positions and in another case sixteen selective positions;

Fig. 5 is a circuit diagram similar to that of polarity of the said source of current.

Fig. 3, but providing an alternative arrangement by which the device can be worked at a distant point regardless of a ground potential which may exist between the point at which the device is situated and the point at which control of the device is exercised;

Fig. 6 is another chart showing the connections to be made to provide ten selective positions of the device;

Fig. 7 is a circuit diagram showing how a tenelement electronic tube can be operated toselectively close one of ten paths therethrough; vand Fig. 8 is another chart showing the connections to be made to provide ten selective settings of the tube.

The device consists essentially of a stator having a magnetic frame I provided with four poles 2, 3, E and 5. Connections are made from ground in series through windings on poles 4 and 2 to terminal A and from ground in series through windings on poles 3 and to terminal B. A rotor comprises a rotatable shaft 6 which carries a permanent magnet I, so it will be easily understood that with terminal A alone connected to a source of current the magnet I will assume either the position shown in Fig. 2 or a position 180 degrees therefrom in accordance with the With both terminals A and B connected to sources of current of different strengths and polarities, the magnet I may be made to assume any desired position. v

The shaft 6 has mounted thereon helically, a number of lugs, such as lug 8. When the terminal A is connected to a source of current of the proper polarity to cause the magnet I to assume the position indicated in Fig. 2, then the first movement is one of rotation so that the lug 8 will -comeinto cooperative relationship with the pair of contact springs 9 and I0, mounted in any convenient manner as indicated schematically by the block of insulating material II. This movement may be extremely rapid. Thereafter a slow-moving contact member I2 infiuenced by the magnetization of the frame I will close a circuit for the energization of an electromagnet I3, which will move the shaft 6 bodily toward the left against the force of spring I4 and cause a connection to be made between springs 9 and I 0. In this manner an appropriate number of pairs of springs may be selectively actuated. :I'he contact member I2 may be rendered slow acting in any accepted and well-' known manner. 'As indicated in Fig. 1, it has sufiicient mass so that when it is energized by the leakage field external to the field structure I its movement will be comparatively slow, The adjustable weight shown mounted on the member I 2 indicates sufficient mass to produce the desired result.

By the aid of Fig. 3 and the cole I of Fig. 4 it will be seen how a set of twelve spring combinations may be selectively operated and by the aid of Fig. 3 and the code 2 of Fig. 4, it will be seen how a set of sixteen spring combinations may be selectively operated. It will be understood that coils l5 and I6 represent windings on poles 4 and 2, respectively, and that coils I1 and I8 represent windings on poles 3 and 5 respectively. The terminals A and B are shown in Fig; 3 as connected to battery terminals by dotted lines. The five terminals connected to batteries I9 and 20 and to resistances 2| and 22 may be interconnected with the terminals A and B to give the desired results charted in Fig. 4. It will, furthermore, be understood that means for making such interconnections maybe incorporated in properly designed keys so that the selection of a set of contacts may be carried out substantially instantaneously. It will further be understood that the difference between the arrangements for code I and for code 2 of Fig. 4 will consist in different values of battery potentials and difierent values of the resistances 2I and 22.

In Fig. 5 an alternative arrangement is shown in which the eii'ects of a ground potential, indicated by the dotted circuit arrangement, may be avoided. This consists in the use of two varistors 23 and 24 and a source of alternating current 25 instead of the direct current sources I9.and

. of Fig. 3. The portion of the circuit to the right of the dotted portion of the two conductors may be a substation circuit, whereas the remainder of the circuit may be at a central oflice. Using the proper values of resistances 26, 21, 28 and 29 and the circuit combinations shown in the chart of Fig. 6, a ten-place selection may be made. This would be useful in a telephone system where the ten-place selection could be used for the registration at the central ofiice of the digits of a telephone number.

The resistances 26 and 21 are provided so that adjustments made therein will make the total series resistance about the same on all lines.

With the arrangement of Fig. 5, only the first and third quadrants-can be used, since currents of opposite polarities cannot be permitted in the two windings. It will be clear that since the operation of the device requires simultaneous fluxes from the two windings, they must both use either the positive or the negative half waves of the alternating current.

The fact. that currents of opposite polarities are not used in any signal prevents the system from being affected by differences in ground potential at the two ends of the line. With the arrangement of Fig. 3, the introduction of such potentials might cause errors in signals belonging to the second or fourth quadrants, since they would increase the current in one winding and decrease that in the other. In the first and third quadrant signals, however, ground potential would merely increase or decrease the voltage applied to both wires and since the position of the rotor or shaft 6 depends merely on the ratio of the currents in the two windings, no error would be caused.

InFig. 7 another form of the invention is illustrated; In this case the equivalent or a stator having two coils in quadrature is provided by the two coils 30 and 3| disposed so as to set up a magnetic field in the tube 32 in any given direction. The tube 32 is constructed and operated in accordance with the Patent 2,217,774 granted October 15, 1940 to A. M. Skellett and when properly energized by the coils 30 and-3| will direct an electron beam from the cathode 33 to any one of the ten anodes 34 to 43, thus closing an electrical circuit to any one of the terminals 44 to 53, respectively.

The two coils 30 and 3| are connected to lines 54 and 55, respectively, which branch out through resistors 56 to 59 to a set of terminals marked 1 to 6. A positive battery 60 and a negative battery 6| are provided with terminals marked and When these battery terminals and the terminals 1 to 6 are variously interconnected according to the 'code of Fig. 8, the circuits connected to terminals 44 to 53 are selectively rendered eflective.

While the values of the battery potentials and the resistances 56 to 59 are not given, it will be understood that they may be chosen so thatthe strength of the combined held from the two coils 30 and 3| will be the same in any position.

It will again be understood that the means for interconnecting the coils, the batteries and the resistors may be of any convenient design of switches or keys.

It will be understood that the invention is capable of other variations and is to be limited only by the following claims.

What is claimed is:

1. A relay comprising a stator having coils in quadrature responsive to selective energization to set up a field in a predetermined number of rotational positions, a polarized rotor, a set of contests for each rotational position of said rotor, magnetic means for moving said rotor longitudinally, and means responsive to said longitudinal movement of said rotor for operating a rotatably selected set of said contacts.

2. A relay comprising a stator having coils in quadrature responsive to selective energization to set up a field in a predetermined number 01 rotational positions, a polarized rotor. a set of con,- tacts for each rotational position of said rotor, magnetic means responsive to the energization of said coils for moving said rotor longitudinally and means responsive to said longitudinal movement of said rotor for operating a rotatably selected set of said contacts.

3. A relay comprising a stator havingcoils in quadrature responsive to selective energization to set up a field in a predetermined number of rotational positions, a rotor polarized by a permanent magnet, a set of contacts for each rotational position of said rotor, magnetic means for moving said rotor longitudinally, and means responsive to said longitudinal movement of said rotor for operating a rotatably selected set of said contacts.

4. A relay comprising a stator having coils in quadrature responsive to selective energization to set up a field ma predetermined number of rotational positions, a polarized rotor, a set of contacts for each rotational position or said rotor, said sets of contacts being arranged in a row parallel to the axis of said rotor, a stem having an axis coinciding with the axis of said rotor and a pin carried by said stem for each said set of contacts, said pins being helically arranged so that in each rotational position of said rotor one of said pins will be moved into cooperative relationship with a corresponding one of said sets or contacts, and magnetic means for movingsaid stem longitudinally to operate said one Of said sets oi contacts. I

5. A relay comprising a stator having coils in quadrature responsive to selective energization to set up a field in a predetermined number of rotational positions, a polarized stator, a set or contacts for each rotational position of said rotor,

- magnetic means for moving said rotor longitudinally, slow-operating means responsive to the energization of said coils for operating said magnetic means, and means responsive to said longitudinal movement of said rotor for operating a rotatably selected set of said contacts.

6. A relay comprising a polarized rotor, a stator having coils in quadrature responsive to energization in various strengths and directions to move said rotor to various rotational positions, a set of contacts for each saidrotational position of said rotor, magnetic means for moving said rotor longitudinally, slow-operating means responsive to the energization of said coils for operating said magnetic means, and means responsive to said longitudinal movement 01' said rotor for operating a rotatably selected set of said contacts.

FRANCIS A. HUBBARD. 

